A compact size signal conditioning circuit for thermocouple linearization and amplification for industrial IoT devices

As the Industrial Internet of Things evolves, ever more data acquisition devices are integrated inside factories, silos, agriculture facilities, industrial facilities, cars and many other applications. One of the most common measured parameter, that also creates the most problems in specific applications, is temperature. There is an abundance of analog temperature transducers, available for engineers and researchers, with varying precision, temperature range, linearity, power consumption, and cost. Besides invasive temperature sensors and transducers, in recent years microwave based temperature measurement methods have been developed. The current paper presents one method of reading thermocouples without the need of a high resolution ADC or digital calculation of complex polynomial functions. The article is focused on the linearization circuit, measurement results, errors and presents a short application using NI WSN nodes as part of IIoT.